Recently, radio telecommunication networks have widely spread. Moreover, the most recent developed networks and/or those networks currently being under development like the so-called third generation or UMTS networks (Universal Mobile Telecommunication System networks) offer an increasing number of services (like internet access, short message services SMS, etc.) to subscribers to the network.
Generally, such UMTS network systems adopt a hierarchic architecture as briefly explained below.
A UMTS network consists of the main parts of a core network CN, a radio access network UTRAN (UMTS terrestrial radio access network), and a user equipment UE. An interface between a user equipment UE (such as a mobile terminal device or mobile station) is referred to as Uu (air interface for uplink UL and downlink DL transmission). An interface between the UTRAN and the core network CN is referred to as Iu.
The core network CN is composed of those parts, which do not relate to the UTRAN such as a mobile switching center MSC and/or a gateway mobile switching center GMSC. A gateway mobile switching center GMSC is adapted to provide an interface of the UMTS network to another network such as the public switched telephone network PSTN or the ISDN network (integrated services digital network) or the Internet.
The UTRAN network consists of radio network subsystems RNS, which communicate with each other via an interface referred to as Iur. An individual radio network subsystem is composed of a radio network controller RNC which communicates with at least one so-called Node_B B via an interface referred to as Iub. A reception area of each Node_B is referred to as cell C.
Herein above, only a rough structural overview of the network system has been given, while it is apparent to those skilled in the art which specific functions and interrelationships exists between the outlines components, so that the networks system need not be described herein in greater detail.
Now, depending on a type of user equipment UE a user utilizes and/or depending on where, i.e. in which radio access network and/or in which radio network subsystem (and/or also of which network operator), the user uses his user equipment, different functions which the user equipment is capable to perform are enabled and/or disabled. Stated in other words, each user equipment has certain capabilities, while not all capabilities are supported by a radio network in which the terminal device is used, or the network offers more functional features than the user equipment is capable to perform.
The capabilities of a user equipment are described in so-called “UE Capability” information in connection with the UMTS network as a third generation telecommunication network. (Formerly, in connection with GSM systems, this kind of information related to terminal devices was referred to as “MS classmark information”). Thus, for effecting communication between a respective user equipment and the radio access network UTRAN, it is necessary that the network has a knowledge of the capabilities of the terminal device.
This will be explained with reference to an example of a connection setup in an existing system, such as for example in the GSM system. (The above explained structure of a UMTS network can to a certain extent be mapped to a GSM system in that a radio network subsystem RNS could correspond to a base station system BSS, a radio network controller RNC could correspond to a base station controller BSC, and a Node_B could to a certain extent be compared to a base station BS).
Now, in the GSM system, when no communication link exists and the user wants to initiate a call, i.e. establish a communication link, an initial random access message requesting for a channel to be assigned is sent from the terminal device MS to the access network. This channel request message CHAN_REQ transmitted on the logical random access channel RACH contains a limited set of information related to the terminal station (user equipment). For example, due to a limited transmission capacity on the RACH channel, this message may merely include an information as to whether the terminal device supports full rate and/or half rate traffic channels.
If a communication can be established, the network sends an access grant message via an access grant channel AGCH to the terminal device and subsequently, dedicated control channels DCCH are established for the signaling between the (previously) requesting terminal device and the radio access network.
After such a signaling link has been established, the terminal device forwards “actual” classmark information (specifying services supported by the terminal device and/or describing the terminal device's capabilities) with an initial Layer 3 message (according to the ISO/OSI layer model) to the network. For example, in the GSM network, such actual classmark information is sent with the first Layer 3 message (=the initial service request message; e.g. a PAGING RESPONSE, LOCATION UPDATING REQUEST, IMSI DETACH, CM SERVICE REQUEST, or CM RE-ESTABLISHMENT REQUEST message). This message is sent by the mobile station to the network piggy-backed in the L2 SABM frames establishing the main signaling link.
Furthermore, a base station controller device BSC has to extract the classmark information from a mobility management MM/connection management CM message before forwarding this message of a higher layer to a mobile service switching center MSC.
For a third generation network like the UTRAN, a proposal has recently been made such that a separate “UE capability” message (corresponding to a GSM classmark message) is to be forwarded from a user equipment UE to the UTRAN immediately after a link has been established.
However, in connection with the above prior solutions or proposals, there are several inconveniences.
Firstly, classmark information (or UE capability information) is received only in Layer 3 signaling, i.e. after a signaling link exists already. Moreover, the classmark information has to be extracted from the higher layer message such as mobility management MM and connection management CM messages. Furthermore, signaling channels like the dedicated control channels SDCCH, SACCH and FACCH are reserved for exchanging measurement reports and can not be used for other purposes. Thus, some initial measurement reports are even “wasted” since there is no actual knowledge of the capabilities of the terminal device at the network side.
In consequence, when getting the (essential or actual) classmark information defining the functional features (e.g. supported services) of the terminal device (user equipment) late, not all features offered by the telecommunication network have been able to be implemented in an optimum way.